Method and apparatus for trimming and butt welding the ends of metal strips, plates, and the like



une 24,

ETHOD H. O. KLINKE v AND APPARATUS FOR TRIMMING AND BUTT WELDING ENDS OFMETAL STRIPS, PLATES AND THE LIKE iled Feb. 8, 1946 THE INVE TOR p N j;K? 4 B i y I a. l 0 V ORNEY;

Patented June 24, 1947 METHOD AND APPARATUS FOR TRIMMING AND BUTTWELDING THE ENDS OF META STRIPS, PLATES, AND THE LIKE Henry 0. Klinke,Forest Hills, N. Y., assignor to Air Reduction Compan poration of NewYork Application February 8, 1946, Serial No. 646,282

11 Claims.

This invention relates to a method and apparatus for trimming and buttwelding the ends of metal strips, plates, and the like.

In processes requiring a continuous supply of strip material, such assome tube welding processes, it is common practice to weld successivenew strip sections to the trailing end of the ad vancin strip materialthat is passing to the welding or other apparatus that requires thecontinuous supply. The new strip sections are successively welded to theend of the last strip section on the advancing strip by providing someslack in the advancing strip so that its trailing end can remainstationary long enough to weld a new strip section to it. In some cases,as in tube welding, the joints where the successive strip sections arewelded to the advancing strip must be butt joints with no overlapping.Ragged edges could be welded together with a lap seam, but since thewelded joints go into the finished tube, it is essential that thethickness of the metal at the welds be substantially the same as thethickness of the metal of the strip. Therefore, unless the stripsections have been previously prepared by trimming the ends, it isnecessary to perform both a cutting operation to trim the ends to bewelded, and a welding operation, within the short period of time duringwhich the trailing end of the advancing strip can be held stationary.

The principal objects of this invention are to provide a method by whichthe ends of metal strip sections, plates, and the like, can be quicklytrimmed by means of oxygen cuttin torches prior to butt welding the endstogether, and an improved apparatus adapted for use in carrying out themethod.

In its preferred form the apparatus comprises welding equipment havingtwo dies each with jaws adapted to grip the end portions of the stripsections at opposite sides of the region where the trimming is to takeplace and the weld is to be effected. A retractable clamp extends intothe space between the welder dies and clamps the adjacent ragged edgeportions of the strip sections that are to be trimmed off. Current isthen supplied to the welder dies. tractable clamp bridges the gapbetween the ends of the strip sections it completes the circuit throughthe portions of the strip sections lying between the welder dies. Thecurrent rapidly heats these portions of the strip sections to red heat,the intensity of the current being initially no greater than required toheat them to this degree. At this temperature the end portions of thestrip sections can be out at very high speed with oxygen cutting torchesso a pair of such torches, mounted on a torch carriage movabletransversely of the metal strip, are caused to traverse the stripsections between the welder dies to cut off the ragged end of eachstrip'sec- Since the re-,

y, Incorporated, a cortion. The retractable clamp is then retracted andcarries with it the two ragged end portions which have been cut from thestrip sections and which are still gripped by the clamp. The welder diesare then brought together to make a butt weld between the trimmed endsof the strip sections.

The method and the preferred form of apparatus for carrying it out areillustrated more or less diagrammatically in the accompanying drawing,the single figure of which is a perspective view of the apparatus, someparts being shown in section taken along a line parallel to thelongitudinal axis of the metal strip.

Referring to the drawing, the last strip section of a strip of metalthat is advancing to apparatus requiring a continuous supply of stripmaterial,

such as a continuous tube welding apparatus, is-

represented at I0. Its rear end portion is held between the jaws l3 andll of a welder die. The forward end portion of a new strip section l5,which is to be butt welded to the strip section It, is held between jawsI! and I8 of another welder die. Preferably, the welding equipment ofwhich the welder dies form a part, is equipment of the flashwelder'type. The two welder dies being spaced apart longitudinally ofthe strip material clamp the end portions of the strip sections alongspaced areas which extend transversely of the strip. r

A retractable clamp, which is preferably a cantilever clamp having upperand lower jaws 2i and 22, can be moved into the space between the welderdies and clamped against the upper and lower faces of the ragged edgeportions of the strip sections [0 and 15. A pair of oxygen cuttingtorches 21 and 28 are mounted on a torch carriage 30 which is movabletransversely of the strip material. Preferably, the torch carriage is ofa well known self-propelled type and runs on a track 3! on the topsurface of the upper cantilever jaw 2 l. The cutting torches are soarranged that when the torch carriage moves along its track, one torchwill cut the strip section l0 transversely to sever its ragged edgeportion at the rear end of the strip section, and the other torch willcut the strip section l5 transversely to sever its ragged edge portionat the forward end of this strip section.

The portions of the two strip sections lying between the welder dies areheated to approximately red heat. This is conveniently accomplished byutilizing current in one of the welding circuits. When the weldingequipment is of the flash welder type equipped with a circuit forsupplying an amount of heat which is used to anneal the weld after it'ismade, the circuit for the annealing heat may be utilized to heat the endportions of the strip sections to the required temperature. 'Thiscircuit is closed and power is supplied by transformer 25 to the welderdies. Since the jaws 2| and 22 of the retractable clamp bridge the gapbetween the ends of the strip sections In and I5, current flows from onewelder die to the other through the portions of the strip sections lyingbetween them and through the jaws of the retractable clamp whichbridge-the gap. This current rapidly heats the endportions of the stripsections to red heat and at this tem-- perature they can be cut at veryhigh speed by rial of the kind that is" fed to continuous tube" weldingapparatus, it may also 'be used for trimming and butt welding plates.and other metal objects-in cases wherethe'greater trimming speed madepossible by the invention is: desirable; In cases where the typeofwelde'd j'ointi producedby resistance pressurewelding equipmenti'sisuitable, for instance in trimming: andrwelding'plates for certain:purposes, the welder dies may: constitute part of that kindof? weldingequipment. How-- ever, when-the invention is-used for triinming andwelding strip sections that makeup. strip material tobe fedto continuoustube welding apparatus, the welder dies are preferably flash welder diesby which flash welded joints will be pro:- duced;

I'clai'm:

1. Apparatus for trimming and butt welding the adjacent ends of metalstrip sections, plates, and the like, comprising two clamping devicesspaced apart longitudinally of the strip sections and extendingtransversely of them for clamping the endportions of thestripsections-at opposite sidesof the region where'the trimmingandwelding is to be effected, a clamp adapted to occupy a positionintermediate said two spaced clamping devices and in that position toclamp the adjacent edge portions of the strip sections to be severed,means for heating theportions of the strip sections between said spacedclamped devices to approximately redheat, and apair of oxygen cuttingtorches "mounted formovement transversely ofthe stripsections betweensaid spaced clamping devices and adapted to cut the end portions of the"strip'sections transversely while they are thus heated to approximatelyred heat to sever the adjacent edgeportions of the strip sections, saidintermediate clamp being retractable from its positionbetween thetwo'spaced clamping devices transversely of the strip sections towithdraw the severed edge portionsof' the strip sections, and saidspaced clamping devices being movable toward each other to effect a buttweld between the trimmed edges of the strip sections when they are atwelding temperature;

2. Apparatus for trimming and butt welding the adjacent ends of'metalstrip sections, plates, andthe like, comprising two clamping devicesspaced apart longitudinally of the strip sections and extendingtransversely of themfor clamping the end portionsofthe strip sections atopposite sides of the region where the trimming and welding is to beeffected, a cantilever clamp adapted to extend into the space betweensaid two clamping devices and in that position to clamp the adjacentedge portions of the strip sections to be severed, means for heating theportions of the strip sections'between said spaced clamping devices toapproximately red heat, and a pair of oxygen cutting torches mounted formovement transversely of the strip sections between said spaced clampingdevices and adapted to cut the end portions of the strip sectionstransversely while they are thus heated to approximately red heat tosever the adjacent edge portions of the strip sections, said cantileverclamp being retractable from its position between the two spacedclamping devices transversely of the strip sections to withdraw thesevered edge portions of the strip sections; and said spaced clampingdevices being movable toward each other to effect a butt-weld betweenthe trimmed edges of the strip sections when they are at weldingtemperature.

3; Apparatus inaccordance with claim 2 in which said. cantilever-clamphas upper-and'l'ower jaws for clamping the adjacent end' portionsof thestrip sections tobe severed and in which the oxygen cutting torches aremounted on a torch carriage guided'along the top surface of'theupperjawof the cantilever clamp.

4. Apparatus for trimming and butt welding the adjacent ends of metalstripsections, plates, and the like, comprising a pair of welder diesspaced apart longitudinally of the strip sections and extendingtransversely of them, said welder dies being adaptedto'clamptheend'portions of the strip sections at opposite sides of theregionwherethetrimming and weldingis to be effected,

clamping means adapted to occupy a position intermediatesaid welder diesand in thatposition -to clamp the adjacent edge-portions of the stripsections-tobesevered, means for initially supplying electric current to'the welderdiesof an intensitysuch that when the currentpasses fromonewelder dietothe other through the endportions of the stripsections'and through the intermediate clamping means which bridges themsaid end portions of the strip sections are'heated to approximately redheat, and a pair of oxygen cutting torchesmounted for movementtransversely of the strip' seotions betweensaid welder dies'andadaptedto cut the end portions ofthe strip'sections transversely while they arethus-heated to approximately red heat to sever the adjacent edgeportions of the strip'sections, said intermediate clamping means, beingretractable fromits position-between the welder dies transversely of thestrip sections to withdraw the severed edge portions-of the stripsections, and saidwelder dies being movable toward each other to effecta butt weld between the'trimmed edges-of the strip sectionsivhen-theyare at welding temperature.

5. Apparatus for trimming and butt welding the adjacent ends of metalstripsections, plates, and the'like, comprising a pair of welder diesspaced apart longitudinally of the strip sections and extendingtransversely of them, saidwelder dies being adaptedto clamp the endportions or the stripsectionsat opposite sides of the region where-thetrimming and-welding isto be eiTected; a cantilever clamp adapted toextend into the space between said Welder dies and in-that posi-'tiontoclampthe adjacent edge. portions of the strip sections to besevered, means for initially supplying electric current tothe Welderdies of an intensity suchthat when the current passes from one welderdie to the other through the end portions of the strip sections andthrough the cantilever clamp which bridges them said end portions of thestrip sections are heated to approximately red heat, and a pair ofoxygen cutting torches mounted for movement transversely of the stripsections between said welder dies and adapted to cut the end portions ofthe strip sections transversely while they are thus heated toapproximately red heat to sever the adjacent edge portions of the stripsections, said cantilever clamp being retractable from its positionbetween the welder dies transversely of the strip sections to withdrawthe severed edge portions of the strip sections, and said welder diesbeing movable toward each other to effect a butt weld between thetrimmed edges of the strip sections when they are at weldingtemperature.

6. Apparatus in accordance with claim 5 in which said cantilever clamphas upper and lower jaws for clamping the adjacent end portions of thestrip sections to be severed, and in which the oxygen cutting torchesare mounted on a torch carriage guided along the top surface of theupper jaw of the cantilever clamp.

7. Apparatus for trimming and flash butt welding the adjacent ends ofmetal strip sections, plates, and the like, comprising a pair of flashwelder dies spaced apart longitudinally of the strip sections andextending transversely of them, said flash welder dies being adapted toclamp the end portions of the strip sections at opposite sides of theregion where the trimming and welding is to be effected, clamping meansadapted to occupy a position intermediate said flash welder dies and inthat position to clamp the adjacent edge portions of the strip sectionsto be severed, means for initially supplying electric current to theflash welder dies of an intensity such that when the current passes fromone welder die to the other through the end portions of the stripsections and through the intermediate clamping means which bridges themsaid end portions of the strip sections are heated to approximately redheat, and a pair of oxygen cutting torches mounted for movementtransversely of the strip sections between said flash welder dies andadapted to cut the end portions of the strip sections transversely whilethey are thus heated to approximately red heat to sever the adjacentedge portions of the strip sections, said intermediate clamping meansbeing retractable from its position between the flash welder diestransversely of the strip sections to withdraw the severed edge portionsof the strip sections, and said flash welder dies being movable towardeach other to effect a flash butt weld between the trimmed edges of thestrip sections when they are at flash welding temperature.

8. The method of trimming and butt welding the adjacent ends of metalstrip sections, plates, and the like, which comprises clamping the endportions of the strip sections at opposite sides of the region where thetrimming and welding is to be effected and along areas which are spacedapart longitudinally of the strip sections and which extend transverselyof them, clamping the adjacent edgeportions of the strip sections to besevered, heating the end portions of the strip sections which lieinwardly of said spaced clamped areas to approximately red heat,thermochemically cutting the end portions of the strip sections alongtransverse lines while they are thus heated to approximately red heat tosever the adjacent edge portions of the strip sections, withdrawing thesevered edge portions of the strip sections while still clamped, andmoving the trimmed and still clamped end portions of the strip sectionstogether to eifect a butt weld between the trimmed edges of the stripsections while they are at welding temperature.

9. The method of trimming and butt welding the adjacent ends of metalstrip sections, plates, and the like, which comprises clamping the endportions of the strip sections at opposite sides of the region where thetrimming and welding is to be eifected and along areas which are spacedapart longitudinally of the strip sections and which extend transverselyof them, clamping the adjacent edge portions of the strip sections to besevered, passing electric current through the end portions of the stripsections which lie inwardly of said spaced clamped areas to heat them toapproximately red heat, thermo-chemically cutting the end portions ofthe strip sections along transverse lines while they are thus heated toapproxim red heat to sever the adjacent edge portions of the stripsections, withdrawing the severed edge portions of the strip sectionswhile still clamped, and moving the trimmed and still clamped endportions of the strip sections together to effect a butt weld betweenthe trimmed edges of the strip sections whil they are at weldingtemperature.

10. The method of trimming and flash butt welding the adjacent ends ofmetal strip sections, plates and the like, which comprises clamping theend portions of the strip sections at opposite sides of the region wherethe trimming and flash welding is to be efiected and along areas whichare spaced apart longitudinally of the strip sections and which extendtransversely of them, clamping the adjacent edge portions of the stripsections to be severed, initially passing electric current through theend portions of the strip sections which lie inwardly of said spacedclamped areas of an intensity such that it will heat them toapproximately red heat, thermo-chemically cutting the end portions ofthe strip sections along transverse lines while they are thus heated toapproximately red heat to sever the adjacent edge portions of the stripsections, withdrawing the severed edge portions of the strip while stillclamped, and moving the trimmed and still clamped end portions of thestrip sections together to effect a flash butt weld between the trimmededges of the strip sections while they are at flash welding temperature.

11. The method of trimming and flash butt welding the adjacent ends ofmetal objects which comprises clamping the end portions of the objectsat opposite sides of the region where the trimming and flash welding isto be effected, initially passing electric current through the endportions of the objects which lie inwardly of the places where theobjects are clamped of an intensity such that it will heat them toapproximately red heat, thermochemically cutting the end portions of theobjects transversely while they are thus heated to approximately redheat to sever the adjacent edge portions of the objects, and moving thetrimmed end portions of the objects together to effect a flash butt weldbetween the trimmed edges while they are at flash welding temperature.

HENRY O. KLINKE.

